Holt 75 Engine

[swh]

Just finished my Holt 75 and have a problem.
Here are the specs:
I am running Coleman lantern fuel
Valve timing is set for the #1 cylinder Intake valve opening at 15 deg ATDC
Ignition timing is set to TDC
Rings are gaped at 0.009"
Engine starts with a couple of quick turns of the flywheel and idles very smooth.
The problem!
After about 10 seconds the exhaust starts to smoke excessively and oil is present at the exhaust pipe opening.
What’s wrong?

 

[gbritnell]

Here's the specs for my Holt:
Intake opens 20 deg. BTDC.
Ignition timing is 15 deg. BTDC.
Engine starts good, idles good and revs good. If I let it idle for a long period of time then rev it up it will smoke but it is fuel smoke because with all the bends in the manifold the fuel tends to puddle. Once I rev it up the smoking clears up. I can clean it up by leaning out the idle but then it won't rev up.
What are you using for a carburetor?
gbritnell

 

[swh]

Thanks for the info George.
The only hit I got when I did a search for valve timing was on a model T forum, where he gave the 15 deg ATDC.
I did build the Holt carburetor and it is the one I’m using, although I have heard others say it doesn’t work.
I have the plans for Jerry Howells 2 jet carburetor in the event I couldn’t make the Holt carb work.
Another question I forgot to ask is what level should the oil be in the crankcase?
At present I have the oil level at the rod journal center. Is this too much?

 

[gbritnell]

Yes your oil level is too high. That might account for the smoking. I keep mine at the bottom of the journal, just so the rod cap dips into the oil.
gbritnell

 

[swh]

George,
Advancing the timing and lowering the oil level seems to have helped, although I still have some smoke.
What is the best method for breaking in a new engine?
Also, I'm curious as to why others could not make the Holt carburetor work; mine seems to operate fine with good idle and high speed.

Regards
Steve

 

[gbritnell]

Hi Steve,
If you have the original Holt carburetor working then you you're on of the few, if not the only one that I know of. Some have used it with modifications while others like myself just gave up and went with another design. Would it be too much to ask if you could post a video of yor engine?
Gbritnell

 

[swh]

George,
I will as soon as i can get a camara.
Here is a Youtube video of a Holt running with a stock carb.
[ame]http://www.youtube.com/watch?v=EUoy3j4NAuU&feature=player_detailpage[/ame]

Steve